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DynatelTM 900/900M SeriesTest SetOperators Manual
September 199678–8093–0453–4 Revision D
Dynatel TM
900/900M Series Test Sets
Operators Manual
The information in this manual is proprietary to 3Mand may not be reprinted or otherwise copied withoutthe express written permission of 3M.
1996 Minnesota Mining & Manufacturing Company
Page i
Table of Contents
Section One – Operation1. INTRODUCTION 1. . . . . . . . . . . . . . . . . . . . . . . . . . 2. 900/900M SERIES TEST SETS 4. . . . . . . . . . . . .
Notes on Using the Test Set 4. . . . . . . . . . . . . . . . . 3. AUTO CAL 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A. Charge Battery 5. . . . . . . . . . . . . . . . . . . . . . . . B. Self Calibration 5. . . . . . . . . . . . . . . . . . . . . . . . C. Access 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D. Battery Type 6. . . . . . . . . . . . . . . . . . . . . . . . . . . E. Identification 6. . . . . . . . . . . . . . . . . . . . . . . . . . . F. Custom Cable 6. . . . . . . . . . . . . . . . . . . . . . . . . G. Other Setups 7. . . . . . . . . . . . . . . . . . . . . . . . .
4. DIAL 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DC Line Test 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . Voltage 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Current 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ohms 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ohms to Distance (Ohms/Ft.) 18. . . . . . . . . . . . Resistance Fault Locate 20. . . . . . . . . . . . . . . . . Tone 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Opens 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Splits 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AC Line Test 48. . . . . . . . . . . . . . . . . . . . . . . . . . . . Ringers 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . REG 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Loss 54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Noise 56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section Two – Special Applications1. MULTIPLE RESISTANCE FAULTS 59. . . . . . . . . . 2. WATER IN CABLE - RESISTANCE
FAULTED PAIR 60. . . . . . . . . . . . . . . . . . . . . . . . . . 3. SECTION ANALYSIS 61. . . . . . . . . . . . . . . . . . . . . 4. LOAD COILS 62. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5. LOCATING OPENS BY RATIO 64. . . . . . . . . . . . . 6. LOCATING OPEN SHIELD 65. . . . . . . . . . . . . . . . 7. TEMPERATURE CONVERSION 66. . . . . . . . . . .
Page ii
Section Three – Specifications2. 955/955M COMBINATION FAULT LOCATOR 67
A. Measurements 67. . . . . . . . . . . . . . . . . . . . . . . . B. Resistance Fault Locate 67. . . . . . . . . . . . . . . C. Outputs 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D. Environment 69. . . . . . . . . . . . . . . . . . . . . . . . . . E. Dimensions 69. . . . . . . . . . . . . . . . . . . . . . . . . . F. Battery Power 69. . . . . . . . . . . . . . . . . . . . . . . .
3. 945/945M SUBSCRIBER LOOP TESTER 70. . . A. Measurements 70. . . . . . . . . . . . . . . . . . . . . . . . B. Outputs 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. Environment 71. . . . . . . . . . . . . . . . . . . . . . . . . . D. Dimensions 71. . . . . . . . . . . . . . . . . . . . . . . . . . E. Battery Power 71. . . . . . . . . . . . . . . . . . . . . . . .
4. 965/965M SUBSCRIBER LOOP ANALYZER 72. A. Measurements 72. . . . . . . . . . . . . . . . . . . . . . . . B. Resistance Fault Locate 73. . . . . . . . . . . . . . . C. Outputs 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D. Environment 75. . . . . . . . . . . . . . . . . . . . . . . . . . E. Dimensions 75. . . . . . . . . . . . . . . . . . . . . . . . . . F. Battery Power 75. . . . . . . . . . . . . . . . . . . . . . . .
Section Four – Care and Maintenance1. TEST LEAD AND BATTERY
INSTALLATION INSTRUCTIONS 77. . . . . . . . . . . 2. BATTERY MAINTENANCE 79. . . . . . . . . . . . . . . .
A. When To Charge or Replace Batteries 81. . . B. Internal Battery Charging 81. . . . . . . . . . . . . . . C. External Battery Charging 81. . . . . . . . . . . . . .
3. CHECK OPENS PERFORMANCE 82. . . . . . . . . . 4. CHECK RESISTANCE FAULT LOCATE
PERFORMANCE 83. . . . . . . . . . . . . . . . . . . . . . . . .
Appendix–Generally Accepted Criteriafor Standard Telephone Service Appendix 1. . .
Page iii
This manual is being issued to reflect the 900 seires and900M series test sets in one manual. This manual includesadditional information and corrections to the previousversions including (but not limited to) some organizationalchanges to aid in use of this manual.
Comments concerning the contents or organization of thisdocument, as well as suggestions for improvement arewelcomed. Direct comments to:
3M Telecom Systems DivisionLab-Technical Communications6801 River Place Blvd.Austin, TX 78726–9000
For Technical Service call 800/426 8688(outside the U.S.A. call 512/984 2575)
Page iv
How to Use This ManualAlthough your test set may not have all the functionsdescribed here, all the 900 Series test sets tell you what todo at every step, including where to connect the test leads.Turn to the tabbed pages for information about each test.
Section One – Operation introduces and describes the900/900M Series test sets, with operating instructions foreach function. Instructions include descriptions of eachtest, hookup instructions, and a step-by-step example ofeach test function.
Section Two – Special Applications containsinstructions for locating multiple resistance faults, wetsections, performing section analysis, compensating forload coils in cable measurement, some special openslocating techniques, and temperature conversion.
Section Three – Specifications
Section Four – Care and Maintenance
Appendix – Generally Accepted Criteria forStandard Telephone Service
Page v
Glossary of Terms
3M 1020B:Testline for two-way gain/slope or step tone functions.
Access:Telephone line or circuit connection to test equipment.
Address:Information specifying a physical location of trunktermination in a switch, or the logical location of thetrunk termination data in the switch computer.
Analog:Any system where data is represented by acontinuously variable range of values, such as thehands of a clock or the needle on a meter.
AWG:American Wire Gauge. A numerical table designatingthe cross-sectional area of wire. The larger the AWGnumber, the smaller the wire.
Balance:The amount of current cancellation along tip and ringconductors. The subscriber hears non-cancelledcurrents as noise metallic. BALANCE (dB) = POWERINFLUENCE minus CIRCUIT NOISE.
C–Message Weighting:This filtering makes measurements of noise more likethe response of the human ear to various frequenciesover a telephone circuit. Sensitivity of the ear drops atfrequencies below 800 Hz, and above 2500 Hz.
Central Office (C.O.):Telephone switching center for connecting calls.
Cursor:A flashing symbol on a display screen indicatingposition for data entry.
Page vi
Database:All of the information stored in a computer availablefor retrieval and updating.
dBm:A measurement of the power of a signal receivedabove a reference power of 1 milliwatt (10-3 watts).
dBrn:(dB reference noise): The reference for noisemeasurement, a level equivalent to a tone at –90dBm. 0 dBrn = –90 dBm and 0 dBm = 90 dBrn.
dBrnC:dBrn measured with C-message weighting.
Decibel (dB):A unit for measuring the relative strength of a signalparameter, such as power or voltage, often used inmeasuring loss or gain of power in a device or circuit.
DLL:Dial Long Line – a loop treatment device to boost theloop current.
Dial Pulse:The method of telephone dialing by alternatelyopening and closing (pulsing) a contact in thetelephone (dialing the digit 7 produces seven pulses).
Dial Up:The means of establishing a connection through thenetwork over public dial ports.
Digital:Information or graphic data that has been translatedinto a discrete numerical value, and therefore can bemanipulated and reproduced without loss of quality.
DTMF:Dual Tone Multiple Frequency – a touch-tone dialfrequency.
Page vii
Ground Resistance:The resistance between the subscriber protectorground and C.O. ground.
Line Loss (Circuit Loss):Measurement of power loss in dBm, measured withflat weighting over the voice frequency band.
Loading, Cable:Adding inductance (load coils) at specific intervalsalong a cable to reduce distortion and improvefrequency response, compensating fortransmission-degrading distributed capacitancebetween conductors.
Loop Current:Current in mA required to operate C.O. equipmentand station apparatus at the subscriber premises.
Loop Treatment (REG., DLL, etc.):This is C.O. extension equipment placed on a pair toovercome excessive line loss.
Loss:Decrease in power (dB) of a transmitted signal.
Maintenance Test Unit (M.T.U.):Device at protector that allows tester to isolatetrouble to premise wiring.
Noise:Signal producing undesirable sound on telephoneline, caused by impedance discontinuities, crosstalk,or other interference.
Noise Metallic (Nm):Noise measured across the tip and ring of a circuitthat the customer actually hears on the line. Thesame as circuit noise, measured in units of dBrnC.
Page viii
Power Influence (PI):Noise measured between ground and the tip and ringconductors shorted together. Not heard by thesubscriber, the power influence affects the amount ofnoise metallic the subscriber hears. The same asnoise-to-ground (Ng), measured in dBrnC.
REG:Range Extender with Gain (loop treatment) boostsC.O. battery voltage and amplifies AC speech signal.
Ringers:The ringer circuit of a subscriber telephone set, wiredtip, wired ring, or bridged. Measured in tenths of aringer, allows identification of nonstandard equipment.
Slope:The rate of change in attenuation relative tofrequency of a transmission line.
Step Tone:A three - nine frequency tone generator used todetect loading problems.
SECTION 1
Page 1
Test Set Operation
1. INTRODUCTION1.1 This manual provides operating instructions for
the Dynatel 900/900M Series test instruments.The first in the series, the 955 and 955M CombinationFault Locators performs dead-cable (vacant pair) diagnostictesting and resistance fault locating as well as opens andsplits test functions and load-coil counting. The 945 and945M Subscriber Loop Testers combine the 955/955Mfunctions (except resistance fault locating and splits) withan active-cable diagnostic routine and its associated tests.The 965 and 965M Subscriber Loop Analyzers combine alltests, diagnostic routines, and fault locating capabilities ofthe 900/900M Series test sets.
Operation
Section 1
Page 2
The Digital World – Some Differences BetweenAnalog and Digital Testing1.2 Each 900/900M Series test set contains a
computer that tests the line and displays theresults. Read the display carefully. The results may lookdifferent and have more information than what you’re usedto.
1.3 Analog meters have relatively low high-resistancelimits; for example, some can read up to 3
Mohms, while others can read up to 30 Mohms. Incomparison, the digital 900/900M Series unit can read highresistance faults up to 100 Mohms.
1.4 With an analog meter, you have to manually movethe clips from across the pair to ring-to-ground
and tip-to-ground, to determine if the fault is a short orground. With just one hookup, the 900/900M Series test settests the pair tip-to-ring, ring-to-ground and tip-to-ground.The unit displays the fault and its value on the displayscreen (see example, next page) at the press of a key on theunit’s front panel.
Operation
Section 1
Page 3
OHMS
AMPERESD.C.
Leakage path
TIPRING
Volt/Ohm Meter Display(Analog Reading)
3 Megohms
SHORT – (High Resistance):
Comparative Displaysof Digital and Analog Readings of a Faulted Pair
900/900M Series Test Set Display(Digital Reading)
1.5 Other analog meters have converted ohms intopoints. The chart on the next page shows
comparative values for ohms and points.
Operation
Section 1
Page 4
OHMS TO POINTS
Ohms Points0 100
6K 9511K 9024K 8040K 7067K 60100K 50150K 40230K 30400K 20900K 102M 53M 0
2. 900/900M Series TEST SET2.1 This section of the operators manual contains
operating instructions for 900/900M Series test setfunctions, including descriptions of each available test,hookup instructions, and step-by-step flowcharts of eachtest function.
Notes on Using the Test Set2.2 DISPLAY – Adjust display visibility by pressing
(up-arrow key) or (down-arrow key) whenthe unit is first turned on. If your set is equipped with abacklight, hold down the (star key) and press the (left-arrow key) to turn the backlight on and off. For a900-T series test set, see its accompanying TerminalEmulation Manual for backlight instructions.
2.3 STORED TELEPHONE NUMBERS – Eightnumbers may be stored under the DIAL key for
general use. Eight numbers each reside under the LOSS
Operation
Section 1
Page 5
key, NOISE key, and in the step tone and 3M 1020Boptions under the AC LINE TEST key. To enter atelephone number, press the DIAL key, LOSS key, orNOISE key. Press the (star key) to advance to theSELECT/EDIT screen. Use the arrow keys to move thecursor, then type the number. Use the OHMS TODISTANCE key to erase a number. Press the DIAL key tostore the number. Press the ON/RESET key to escape theprogram without dialing.
3. AUTO CAL3.1 The AUTO CAL key gives you access to the
following maintenance and accessory functions.Use the up- and down-arrow keys to move the cursor toyour choice, then press the (star) key to activate thefunction.
A. Charge Battery3.2 For rechargeable batteries only, use this option
and follow the displayed instructions to use theinternal battery charger. The unit determines when thebatteries are fully charged and turns itself off automatically.
Warning:Never try to charge a non-rechargeable battery. Damage to thebattery or personal injury from explosion may result.
B. Self Calibration3.3 To maintain accuracy, use this option to
self-calibrate the unit every day and duringtemperature changes. Press the (star) key to selectSELF CALIBRATION , then short all the test clipstogether. Press the (star) key. The unit displays“PLEASE WAIT” while it self-calibrates, then “beeps”and instructs you to disconnect the leads and press the (star) key. When you have disconnected the leads, and
Operation
Section 1
Page 6
made sure they are not shorting against one another, pressthe (star) key and wait while the unit performs a RAM(random-access memory) test. The screen displays “SELFCALIBRATIONS ARE COMPLETED ✱ .” Press the (star) key to return to the AUTO CAL menu. If the unitfails self calibration, return it for service. The onlyexception may be if the error message is “OPEN TESTLEAD ,” a condition that may be solved by replacing thetest lead assembly. (See the phone number for 3MTechnical Service in the front of this manual.)
C. Access3.4 ACCESS has no user function. If you select this
option, press the Reset key to continue.
D. Battery Type3.5 To control charging, the unit must know what type
batteries it contains. Select this function, thenpress either the (star) key for rechargeablenickel-cadmium batteries, or the (pound) key for drycells (alkaline batteries).
3.6 To replace the batteries, refer to Section Four,“Care and Maintenance” in this manual.
E. Identification3.7 This function displays the unit’s model, serial,
version, and terminal identification numbers.Press the (star) key to return to the menu.
F. Custom Cable3.8 Use this option to program cable capacitance into
the unit for use on non-standard cables. Type themutual and tip-ground capacitances as requested. You willuse these cable specifications when you select theCUSTOM CABLE option from the CABLE TYPE menuin the OPENS test routines.
Operation
Section 1
Page 7
3.9 To determine a cable’s capacitance, press theOPENS key. Press the (star) key to select
NORMAL MODE , then wait. When the display changes,press the (pound) key to call up the OPENS menu.
Move the cursor to CALIBRATE TO CABLE and pressthe (star) key. The display tells you to connect the blackand red leads to a reference pair of known length in thecable, and connect the green lead to grounded shield. Youmust be hooked up to a non-standard cable of knownlength. Press the (star) key, then enter the length andpress the (star) key again. The unit displays thecalibration results. Press the AUTO CAL key and followthe instructions in para. ���� above, to program thecapacitance under the CUSTOM CABLE option.
G. Other Setups
3.10 Use this option to control the sound of thekeystroke “beeps.” For the 900-T series test
sets, use this option to setup the real-time clock and viewthe log which shows information about the last time theset was on the battery charger.
3.11 To setup the clock, use the arrow key to move thecursor next to the “setup clock” option, and press
the (star key). Use the arrow keys or numeric keypadto edit the number. Enter the time by pressing the (starkey). Next, use the arrow keys or numeric keypad to editthe date. Enter the date using the (star key).
3.12 To view the battery-charge log, use the arrow keyto move the cursor next to the “xxxxxxx” option,
and press the (star key). The battery-charge log showsthe beginning and ending dates and times of the lastcharging. The first charging voltage and current aredisplayed, along with the percentage of charge capacity andthe bettery voltage before the charging cycle begins.
Operation
Section 1
Page 8
4. DIAL
4.1 DIAL lets you connect to a working line, monitorit for conversation, then dial any number such as
for battery kill, automatic number announcing (ANA),voice dispatch systems, loss or noise testing, or to listen tothe called party. When the number is dialed, you can pressthe LOSS or NOISE keys to start those test routines. Theunit can provide 1-second ring ground (ground start) ifopen tip is detected. Some units are optionally equipped totest for caller I.D. and message waiting.
Example – Dial Number
RED to RINGBLACK to TIPGREEN to GROUND
Hookup: R
B
G
Use arrow keys tomove cursor; use keypad to enter number.
Disregard this step if the unit is on.
Dial type menu
Turn unit on.
Unit monitorsline
Endof
Test
Press # for groundstart, otherwise, press *
Unit dialsnumber.
On
Reset
DIAL
Use arrow keys tomove cursor to dialtype option.
To dial, go off-hook when instructed on the display.
Choose touch-tone or dialpulse. “Manual” allows you toenter additional access digits.
To select a number on thescreen, line up the cursor withthe number, then press DIAL.To erase a digit, press theOhms to Distance key. In auto-matic dial mode, move the cur-sor to the left to type a numberwith more than 7 digits.
DIAL
DIAL
When the number is dialed, youcan press the LOSS or NOISEkeys to go directly into thosetest routines, or monitor voice.
Listen for dial tone.
OR
OR
OR
Operation
Section 1
Page 9
Example – Caller I.D. Option
RED to RINGBLACK to TIP
Hookup: R
B
Disregard this step if the unit is on.
Timing and carrierlevel parametersinformation display
Turn unit on.
Select to dialor caller I.D.
Endof
Test
On
Reset
DIAL
Unit monitors line,displays caller I.D.
You can press the * keyto go to number dialing.
Received datadisplayed inhexadecimal format.
The data displayedincludes seizurecharacters (hex 55) and“ - - ” to indicate aperiod of about 10 ms inwhich no character wasreceived.
The unit monitors the line formessage waiting signal, andindicates if the message wait-ing light is off or on.
OR
OR
Operation
Section 1
Page 10
DC Line Test
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
About DC Line TestUse the automatic DC Line Test routine to evaluate avacant pair being placed into service or any pair withsuspected problems.
Attach the leads, then turn the unit on.
Always verify results with appropriate manual tests (bluekeys) before taking corrective action.
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testing procedure)follow standard procedures for de-energizing and dischargingcables.
Operation
Section 1
Page 11
DC Line Test
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
88844
GO TORFL1
NOYES
GO TO AC LINETEST2
1RFL = Resistance Fault Locate (not available in 945/945M)2 Not available in 955/955M.
DC LINE TEST
EXTENDERS
VOLTAGE
OHMS
GROUND CABLE TYPE
CURRENT OPENS
DIAL TONE? FAULT? YES
NOSTATICYES
NO RINGERS
ENDof
TEST
Note: On some floating-tip switches such as #5 ESS, groundresistance cannot be measured because the switch operateson a floating ground.
Available in 900-T-Series test sets only:
NO STORE RESULTS? YES
EDIT TITLE
Operation
Section 1
Page 12
Voltage
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
About the Voltage TestThe VOLTAGE key detects and measures for central officebattery or foreign DC and AC voltages on a pair, updatingthe measurement continually.
Note: Voltage accuracy can be affected when source impedanceexceeds the 900/900M Series Test Set input impedance of 1.11Megohms. The user can compute the true voltage readingconsidering the 1.11 Megohms input impedance if accuracy isrequired.
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testing procedure)follow standard procedures for de-energizing and dischargingcables.
Operation
Section 1
Page 13
Voltage
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
Voltage
On
Reset
You can continue to checkdifferent configurations bypressing the ✽ and # keys.
Disregard this step if the unit is on.
Show ring–groundVDC results
Show ring-groundVAC results
Turn unit on.
Run test, showtip-ring VDCresults
Endof
Test
Show tip-ground VDCresults
Show tip-ground VACresults
Show tip-ring VACresults
Show ring-groundVDC results
Press any test key to get out of the test program.
OR
OR
Operation
Section 1
Page 14
Current
RED to RINGBLACK to TIPGREEN to GROUND
Hookup:R
B
G
About the Current TestThe CURRENT key measures DC current on thesubscriber loop to see if the telephone set has enoughpower for operation, continually updating the information.On the 945/945M and 965/965M, the CURRENT keyfunction also tests ground resistance to check integrity ofthe ground connection at the station protector.
Press the CURRENT key, and the unit applies a 430 ohmshort across the pair to simulate an off-hook condition. Theunit displays loop current in milliamps and updates thereading about two times per second.
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testing procedure)follow standard procedures for de-energizing and dischargingcables.
Operation
Section 1
Page 15
Current
RED to RINGBLACK to TIPGREEN to GROUND
Hookup:R
B
G
On
Reset
Current
Turn unit on.
Endof
Test
Check current,show loopcurrent in mA.1
Show station groundresistance
Show loop current inmA.
On the 945/945M and965/965M units only, you canpress the # (pound key) toswitch the display from loopcurrent to station groundresistance and back.
Disregard this step if the unit is on.
Note: On some floating-tip switches such as #5 ESS, groundresistance cannot be measured because the switch operateson a floating ground.
1 To measure RING TO GROUND current, move the blacklead and connect it to ground. The unit automatically makesthe measurement and displays the result.
OR
OR
Operation
Section 1
Page 16
Ohms
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
About the Ohms TestThe OHMS key measures resistance between conductors,or from a conductor to ground. Measurements aredisplayed in ohms and points.
Measurements can fluctuate with power influence,variations in fault resistance or C.O. battery level, or dirtytest clips (keep them clean). A rising or falling toneindicates large resistance fluctuations.
Use the OHMS key to test the good and faulty conductorsbefore using the RESISTANCE FAULT LOCATE key.
Use the OHMS key with the OHMS TO DISTANCE keyto estimate the distance to a solid short or ground.
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testing procedure)follow standard procedures for de-energizing and dischargingcables.
Operation
Section 1
Page 17
Ohms
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
Turn unit on.
Measure, show ring-to-ground resistance
Measure, show tip-to-ground resistance
You can press the ohms todistance key to convert theresistance measurement todistance, or press any other testkey to exit this test program.
Disregard this step if the unit is on.
Endof
Test
Measure, showtip-to-ringresistance
On
Reset
Ohms
The letters “CO” on thedisplay indicate battery onthe line, while loopresistances is beingmeasured.
or
or
Operation
Section 1
Page 18
Ohms to Distance Hookup: none required
About the Ohms to Distance ConversionWhen you encounter a SOLID SHORT (0 Ohms), you canfind the equivalent distance in feet/meters by convertingthe ohms value with the OHMS TO DISTANCE key. Bymeasuring the resistance with the OHMS key first, thenpressing the OHMS TO DISTANCE key, the conversionis automatically calculated.
Note: When the fault is a SOLID SHORT (0 ohms), divide thedistance by two. You cannot calculate the distance to “light” or“wet” troubles using the OHMS TO DISTANCE function.
You can also use the keypad to enter the value to beconverted. Remember, this function is a calculator -- it doesnot replace the resistance fault locate measurements.
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testing procedure)follow standard procedures for de-energizing and dischargingcables.
Temperature is an important factor in ohms-to-distance ordistance-to-ohms conversions. The unit defaults to thetemperature selected in the resistance fault locate functionset-ups; you can also choose to change the temperaturewith the OHMS TO DISTANCE key. To enter atemperature less than zero, type the value, then press theOHMS TO DISTANCE key to enter the value as anegative.
Operation
Section 1
Page 19
Ohms to DistanceHookup: none required
Ohmsto
Dist.
Endof
Test
Select � to dist,distance to �, ortemperature.
The unit uses the temperaturelast used by resistance faultlocate unless you change it.For this example, select settemperature.
Turn unit on.Disregard this step if the unit is on.
Use arrow keys to movecursor; use keypad toenter amount to convert.
Unit calculates anddisplays equivalentamount.
Use arrow keys tomove cursor to option.
Enter amount to beconverted.
Select wire gauge
Use arrow keys to movecursor to wiregauge/size.
Select temperature.
Use arrow keys to movecursor; use keypad toenter temperature.
Select ohms todistance, distance toohms, or temperature.
Use arrow keys tomove cursor to ohms todistance option.
To enter a temperature lessthan zero, type the number,then press the OHMS TODISTANCE key next,instead of the ✽ (star key),to enter it as a negativenumber. Then continue asshown.
The unit also displays thewire gauge and temperatureused to make calculation.When the fault is a short,divide the distance by two.To exit the results display,press the up- or down-arrowkey.
OnReset
or
or
Operation
Section 1
Page 20
Resistance Fault LocateHook-up: As instructed on the unit’s display screen– varies by application (see page 23)
About Resistance Fault LocateThe RESISTANCE FAULT LOCATE (RFL) functionmeasures the distance to the fault (DTF); distance fromthe strap to the fault (STF); distance to the strap (DTS);and distance to a splice (on multi-gauge cable of knowndistance to strap).
First, test good and faulty conductors with the OHMS key;test continuity with the OPENS key.
At the end of the test, 900-T-Series units have the option ofstoring the results for later retrieval in the terminal mode(for more information, see the Terminal Emulation manualfor your unit).
A detailed setups chart and examples follow the RFLflowchart. There are four major set-ups:
a. Unit measures DTS (distance to strap)
b. DTS known
c. Fault locate –– multiple gauge
d. Splice locate –– multiple gauge
In RFL mode, the display “XX NULL” indicates anautomatic null operation required in the measurement.During the distance-to-fault (DTF) measurement, thedisplay “XX.XXX%” indicates fault location relative todistance to strap (DTS) (e.g., 50% indicates halfway tostrap).
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testingprocedure) follow standard procedures for de-energizing anddischarging cables.
Operation
Section 1
Page 21
Resistance Fault Locate
Hook-up: As instructed on the unit’s display screen– varies by application (see p. 23)
Turn uniton.
Disregard this step if the unit ison.
Storedsetupsoption
Use stored set-ups
Endof
Test
Hookup instructions
Fault resistance,strap checks
The display may tell you to “wait”during the tests.
The results depend on the testsyou specified in the set-upsearlier.“Please wait.” You may see “ACDETECTED, PUSH # TO STOP”during a difficult test.You can press the # (pound key)to repeat the test.
DTS, temperature,or splice location
Continue RFLmeasurement
DTF, STF, DTSresults
Additional message,if any.
Use up- and down-arrow keys tosee all the instructions. Continueas instructed.
DTS = Distance to strapDTF = Distance to faultSTF = Distance strap to fault
OnReset
This is the last used setup (starthere if coming from RFL setupson page 22).
If the unit tells you to move closerto the fault, move the unit andstraps nearer the fault and retest;look for similar faults on otherpairs. Check good conductorresistance; use only if goodconductor readings are 500 timesgreater than on fault pair(example: good conductorreadings = 45 M ohms and faultpair readings = 90 k ohms).
EnterUse the keyboard totype title, and press Enter to save it.
At the end of the test, the T-seriesunit prompts you to store theresults. Press the # (pound) key ifyou do not want to save them.The default title contains the timeand date of test. Press the Esckey to accept it without editing.(See Terminal Emulation manualfor more information on storingand retrieving test results.)
1900T-Series units only
Edit results title1
ResFault
Locate
OR
OR
Operation
Section 1
Page 22
RFL Setups
NUMBEROF SECTIONS
TEMPSELECT
OHMS
CONTINUE
GAUGE, LENGTH
SELECTGAUGE
MULTIPLEGAUGE
FEET
NUMBEROF SECTIONS
DTSKNOWN
SINGLEGAUGE
SELECTGAUGE
ENTER LENGTH
ENTERTEMP
GO TO RESISTANCEFAULT LOCATE
FLOWCHART, p. 21
CHANGESETUPS
TURN SET ONPRESS RES FLT
LOCATE KEY.
SETUPSDISPLAY
USESETUPS
MEASUREDTS
OHMS
USE DEFAULT
FEET
SINGLEGAUGE
CHECKSECTIONS
MULTIPLEGAUGE
CONTINUE
SELECTHOOKUP
CHECKSECTIONS
GAUGE, LENGTH
*RTS = Resistance to Strap
ENTERRTS*
Note: Contact your 3M Technical Service Representative atthe number shown in the front of this manual for a copy ofField Note #2 with detailed instructions on estimating cabletemperature.
FEET OR OHMS
FEETOR OHMS
Operation
Section 1
Page 23
RFL Examples
These examples use the Cable Self Test Circuit, (below).Connect the leads RED to R, BLACK to B, GREEN to G,and YELLOW to Y. In the field, hookups vary with theapplication. Be sure to hook up the unit as the displayscreen instructs.
Cable Self TestCircuit
R B G Y
Faulted Pair
Good Pair
Red to faulted ring
Black to faulted tip
Separate Good Pair for short
Yellow to Good 2
Green to Good 1Good 1
Good 2
Common end to faulted ring
Strap End 2 to Good 2
Strap End 1to Good 1
Straps at Far End
Separate Good Pair for ground or battery cross
Black to reference (inthis case, to ground)
Red to faulted ring
Yellow to Good 2
Green to Good 1
Common end to faulted ring
Strap End 2 to Good 2
Strap End 1to Good 1
Straps at Far End
Good Pair
Good 1
Good 2
Examples of Possible RFL Hookups:
Single Pair for ground or battery cross
Green to Good Conductor
Black to reference (in thiscase, to ground)
Strap End 1 to Good Conductor –Strap End 2 not used
Red to faulted conductor
Straps at Far End
Common end to faulted conductor
Operation
Section 1
Page 24
RFL Example 1 – Unit Measures DTS
Display distance inunits of feet or meters
Unit measures DTS
Temperature options
Select gauge
Select hookups
Use separate goodpair hookup
Setups summary
For this example, press the ✽(star key) to use thetemperature default (21°C or70°F)
The display summarizes thesetups you just entered.
Disregard this step if the unit ison.
For this example, use 19 AWG.or .912 mm
The numbers displayed mayvary due to variations in theresistors in the Cable Self TestCircuit. See page 85 for limits.
Endof
Test
Hookup instructions
Fault resistance,strap checks
In the field, use the arrow keysto view all the hookup instruc-tions.
DTF=1210 ft/369 mSTF= 11120 ft/3319 mDTS=12100 ft/3688 m
DTS results:DTS=12100 ft/3688 m
ResFault
Locate
Turn unit on.
Stored setups ––Change setups
OnReset
Use arrow keys toline up ✽ with 19AWG or .912 mm
OR
OR
Operation
Section 1
Page 25
RFL Example 2 – DTS Known (Compute Temperature)
Hookup instructions
Setups summary
Use separate goodpair hookup
Select hookups
Use arrow keys tomove cursor; usenumber keypad toenter DTS: 12100 ftor 3688 m
Enter distance to strap (DTS)
Use arrow keys toline up ✽ with 19AWG or .912 mm
DTS known
Select gauge
Disregard this step if the unitis on.
Always check the setups.Press the ✽ (star key) to usethe stored setups if they arecorrect.
continued on next page...
For this example, use 19AWG or .912 mm.
The display summarizes thesetups just entered. Press the✽ (star key) to use them asdisplayed.
ResFault
Locate
Turn unit on.
Stored setups ––Change setups
OnReset
Display distance inunits of feet or meters
OR
OR
Operation
Section 1
Page 26
RFL Example 2, continued
Fault resistance,strap checks
In the field, use the arrowkeys here to view the rest ofthe instructions and continuemaking the hookup.
The display may tell you“wait” while the tests run.
You can press the # (poundkey) to repeat the test.
Display computedtemperature
Additional message, ifany
Endof
Test
Continue hookup asinstructed
You can press the # (poundkey) to repeat thetemperature calculation.
Continue hookup asinstructed
continued from previous page...
DTF=1210 ft/369 mSTF= 11120 ft/3319 mDTS=12100 ft/3688 m
The numbers displayed mayvary due to variations in theresistors in the Cable Self TestCircuit. See page 85 for limits.
Operation
Section 1
Page 27
RFL Example 3Fault Locate – Multiple Gauge
1. Set up the unit for the locate:
Strap
Unit measures DTSTemp. 70° F or 21° C3 sections
TestSet
Section 1 Section 2 Section 3
Unit measure DTS
ResFault
Locate
Turn unit on.
Stored setups –Change setups
Temperature
Use arrow keys tomove cursor to“multiple gauge”
Press the ✽ (star key) to usethe stored setups if they arecorrect.
continued on next page...
Gauge selection
Number of sectionsin cable
Use keypad to enternumber of sections: 3
For this example, use threesections.
OnReset
Display distance inunits of feet or meters
For this example, press the ✽(star key) to use thetemperature default (21°C or70°F)
OR
OR
Operation
Section 1
Page 28
RFL Example 3, continuedFault Locate – Multiple Gauge
2. Set up for the first section:
Strap
TestSet
205 ft or 63 m
26 AWGor .4 mm
Pick section 1 gauge
Use arrow keys to lineup ✽ with 26 AWG or.4mm
continued on next page...
For this example, use26 AWG or .4 mm.
Use keypad to entersection length: 205 ftor 63 m.
Section 1 length
continued from previous page...
Operation
Section 1
Page 29
RFL Example 3, continuedFault Locate – Multiple Gauge
3. Set up for the second section:
1179 ft or 359 m
24 AWGor .5 mm
Strap
TestSet
205 ft or 63 m
26 AWGor .4 mm
Use arrow keys to lineup ✽ with 24 AWG or.5 mm
Length of section 2
For this example, use 24 AWG or .5 mm.
Use keypad to enterlength of section:1179 ft or 359 m.
Pick section 2 gauge
continued on next page...
continued from previous page...
Operation
Section 1
Page 30
RFL Example 3, continuedFault Locate – Multiple Gauge
4. Set up for the third section:
Strap
TestSet
22 AWGor .7 mm
unknown1179 ft or 359 m
24 AWGor .5 mm
205 ft or 63 m
26 AWGor .4 mm
Pick section 3 gauge
Use arrow keys to lineup ✽ with 22 AWG or.7 mm.
Length of section 3 –unknown
On multiple gauge faultlocate, one section must beentered as “unknown ,”even if you know it.
continued on next page...
continued from previous page...
For this example, use 22 AWG or .7 mm.
Operation
Section 1
Page 31
RFL Example 3, continuedFault Locate – Multiple Gauge
5. Hookup and measurement:
Strap
TestSet
DTS = 5046 ft or 1721 mDTF = 255 ft or 76 m
STF = 4791 ft or 1645 m
DTS
DTF STF
DTF=255 ft/76 m Sec. 2 STF=4791 ft/1645 mDTS=5046 ft/1721 m
DTS 5046 ft or 1721 m
Fault resistance, strapchecks
Test set, straps hookupinstruction
Stored setups –continue with test
Continue test
Select hookup:separate good pair
Endof Test
In the field, use the arrowkeys here to view the rest ofthe instructions and continuemaking the hookup.
The stored setups displayshould say “multiple gauge.”
In this example, the displayshows that the fault is insection 2.
continued from previous page...
Additional message,if any
The numbers displayed mayvary due to variations in theresistors in the Cable Self TestCircuit. See page 85 for limits.
Operation
Section 1
Page 32
RFL Example 4Splice Locate – Multiple Gauge
1. Set up the unit for the locate:
Test Set
DTS known 2500 ft/762 mTemp. 70 ° F or 21 ° C 2 sections
HouseProtector
Strap
Turn unit on.
Stored setups ––Change setups
DTS known
Display units in feet ormeters
Gauge select menu
Use arrow keys toselect multiple gauge
Number of sectionsin cable
Use keypad to enternumber of sections: 2
For splice locate, you mustuse only two sections.
continued on next page...
ResFault
Locate
OnReset OR
OR
Operation
Section 1
Page 33
RFL Example 4, continuedSplice Locate – Multiple Gauge
2. Set up for the first section:
“unknown”
Test Set
HouseProtector
24 AWG or .511 mm
Strap
Pick section 1 gauge
Use arrow keys to lineup ✽ with 24 AWG or .511 mm
Section 1 length –unknown
continued on next page...
continued from previous page...
For this example, use 24 AWG or .511 mm.
Operation
Section 1
Page 34
RFL Example 4, continuedSplice Locate – Multiple Gauge
3. Set up the next section:
26 AWG or .4 mm
“unknown”“unknown”
Test Set
HouseProtector
24 AWG or .511 mm
Strap
Continue test
Length of section 2 –unknown
Use arrow keys to lineup ✽ with 26 AWG or.4 mm.
Pick section 2 gauge(wire size)
For this example, use26 AWG or .4 mm.
continued from previous page...
continued on next page...
Operation
Section 1
Page 35
RFL Example 4, continuedSplice Locate – Multiple Gauge
4. Complete the setups:
26 AWG or .4 mm
“unknown”“unknown”
Test Set
HouseProtector
24 AWG or .511 mm
Strap
Stored setups –splice locate
Cable temperature
Enter DTS (distanceto straps)
Select hookup –separate good pair
Use arrow keys tomove cursor; usekeypad to enter DTS:2500 ft or 762 m
Use the arrow keys to seethe rest of the setups.
Use the default, 21° C or70° F , for this example.
continued from previous page...
continued on next page...
Operation
Section 1
Page 36
RFL Example 4, continuedSplice Locate – Multiple Gauge
5. Hookup and measurement:
Test Set
Sec. 1 = 330 ft/114 mSec. 2 = 2121 ft/648 m
Results:
330 ft/114 m
Strap
26 AWG or .4 mm24 AWG or .511 mm
2121 ft/648 m
Hookup instruction
Additional message,if any
Fault resistance,strap checks
Calculated SpliceSec 1=330 ft/114 mSec 2=2121 ft/648 m;DTS=2500 ft/762 m
DTF=360 ft/115 m STF=2140 ft/647 m DTS=2500 ft/762 m Sec 2
Do Fault Locate
Endof Test
In this example, the displayshows that the fault is insection 2.
continued from previous page...
In the field, you would usethe arrow keys here to viewthe rest of the instructionsand continue making thehookup as instructed.
The numbers displayed mayvary due to variations in theresistors in the Cable Self TestCircuit. See page 85 for limits.
Operation
Section 1
Page 37
Notes on RFL
The set computes a measurement accuracy value based onthe set accuracy, hookup, cable length and fault resistancemagnitude. Depending on this value, the set may tell youto move closer and measure. Move the set and straps to apoint on the cable near the fault and re-test. Look forsimilar faults on other pairs.
Leakage resistance between the reference lead and thegood pair or good conductor affects fault locationmeasurement accuracy. Test the good conductor/pair forleakage faults (results displayed prior to strap checksbetween red and black), and use them only if the faultmagnitude is more than 500 times the magnitude of thefaulted conductor.
The “good conductor” used in separate good pairhookup mode does not have to match the length andgauge of the faulted pair. However, in single pair hookupmode, fault location accuracy depends on the “goodconductor” being the same length, gauge, and preferablyin the same pair or cable group. For example, if the goodconductor is shorter than the faulted conductor, or is alarger wire diameter than the faulted conductor, the testset will give erroneous fault location results. In a case likethis, if the actual fault was near the strap end, the test setcould show a fault location beyond the strap end with anegative distance to fault.
During distance or temperature measurements, if the testset encounters excessive AC power line influence,metallic noise, or high fault resistance, it displaysinformation with the following message that allows you tocomplete the measurement operation:
AC DETECTEDXXXX NULL* PUSH # TO STOP
In this case, the measurement time can be up to twominutes longer than normal while the test set attempts tocomplete the measurements. You can stop themeasurement any time after the “PUSH # TO STOP”message appears, but the results are more accurate in mostcases if you wait as long as practical before manuallystopping the measurement (by pressing the (pound)key).
Operation
Section 1
Page 38
Tone
RED to the CONDUCTOR TO BE IDENTIFIEDBLACK to GROUNDGREEN not used
Hookup: For pair identification:
RED to TIP and RINGBLACK to GROUNDGREEN not used
For louder tone (dead pairs only):
R
B
R
B
Hookup: For loss or gain/slope measuremen ts:
RED to RINGBLACK to TIPGREEN not used
R
B
About the Tone FunctionThe tone function provides tone for pair identification.The unit can send tone for two hours before automaticshut-off.
With the TONE key, you can apply precision tone to thecable for loss measurements. With the 965/965M, youcan also apply tone of any user-entered frequency andamplitude for loss or gain/slope measurements.
For the specific tone output of your test set, see SectionThree, “Specifications.”
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testingprocedure) follow standard procedures for de-energizing anddischarging cables.
Operation
Section 1
Page 39
Tone
RED to the CONDUCTOR TO BE IDENTIFIEDBLACK to GROUNDGREEN not used
Hookup: For pair identification:
RED to TIP and RINGBLACK to GROUNDGREEN not used
For louder tone (dead pairs only):
R
B
R
B
Hookup: For loss or gain/slope measuremen ts:
RED to RINGBLACK to TIPGREEN not used
R
B
On
Reset
Tone
Turn unit on.Disregard this step if the unit is on.
Tone selectoptions.
Move ✽ to line upwith frequencyneeded.
Endof
Test
Loud tone on the speakerindicates complete loops andloops less than 500 ohms. Softtone indicates loops of greaterthan 500 ohms.
If you choose an ID tone, youcan choose to send interruptedtone by pressing the ✽ (starkey), or continuous tone bypressing the # (pound key).Interrupted mode makes tonemore distinctive for use with anamplifier while identifying pairson a cable.
Unit sends continuoustone at selectedfrequency.
Unit sends tone; testset speaker is off, soyou do not hear it.
Unit stops sendingtone.
You can select tone for loss andgain/slope tests. After enteringyour selection, press the ✽ (starkey) to send continuous tone.With the 965/965M only, youcan select user entry and typein the frequency and amplitude.
OR
OR
Operation
Section 1
Page 40
Opens
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
About the Opens TestUse the OPENS key to detect and measure the distanceto an open, partial open or “dirty” open. You can alsomeasure pair length; distance to a split due to an impropersplice; and detect bridge taps, water in the cable, anddetect and count load coils*.
Note: See Section 1, para. 3.8 on page 6 to program customcable characteristics using the AUTO CAL key. See Section 4“Care and Maintenance” for instructions on how to check theOPENS performance.
The test set has two Opens functions: normal and special.Use the special mode on cables shorter than 10,000 feetfor opens with resistance faults, crossed battery, or highnoise. The special mode does not read through load coils.Add 10% to the measured mutual length for the distanceto the first load coil.
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testingprocedure) follow standard procedures for de-energizing anddischarging cables.
* Early software versions of the 900/900M Series test sets arenot equipped to count load coils. To determine if your set isequipped to do load coil counts, press the OPENS key. If theset is so equipped, the menu includes a “load coil count”option.
Operation
Section 1
Page 41
Opens
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
Turn unit on.On
Reset
Opens
Both Normal and Specialmodes operate the same.For this example, selectNormal mode.
Normal, Special,Split Locate, LoadCoil Count1
Move ✽ to select testtype– Normal
Display shows lastopens set-up
Cable type menu
Select cable type,calibrate to cable, ormeasure capacitance
Length measurement.
Disregard this step if the unit is on.
Endof
Test
Press the ✽ (star key) toswitch the display betweentip, ring and mutualmeasurements. Mutual isnot used for locating opens.
You can measure the cablecapacitance, or measure tothe open using one of fivestandard cable profiles, orcalibrate to cable. Use theAUTO CAL key to set upCUSTOM CABLE (see Sec.1). For this example, selectaircore cable.
OR
OR
Note: An “overrange” message on the display means the pair islonger than the unit can measure, or the resistance fault is tooheavy. Try the special mode to locate the open, or use the OHMSkey to verify.1 Early software versions of the 900/900M Series test sets are notequipped to count load coils. To determine if your set is equipped todo load coil counts, press the OPENS key. If the set is so equipped,the menu includes a “load coil count” option. See Section 2 of thismanual “Special Applications” for more information on load coils,and an example of the load coil count procedure.
Opens Example: Calibrate to CableThe unit is calibrated for cables of standard capacitance.For greatest measurement accuracy, use the “calibrate tocable” option.
Operation
Section 1
Page 42
For this example, connect the leadsto the Cable Self Test Circuit (shownhere) RED to R and BLACK to Bonly.
R B G Y
Turn unit on.
Both Normal and Specialmodes operate the same.For this example, selectNormal mode.
Normal, Special,Split Locate, LoadCoil Count
Enter reference pairlength: 440 ft/43 m
Move ✽ to select testtype– Normal
Display shows lastopens set-up
Cable type menu
Select cable type,calibrate to cable, ormeasure capacitance
Connect red, black clipsto pair of known length,green to shield
Calibration results fortip, ring and mutual
Length measurementresults.
Disregard this step if the unitis on.
For this example, selectcalibrate to cable.
Use arrow keys to movecursor.
Endof
Test
The results are now storedunder the “Use Calibration”option in the cable typemenu. Press the ✽ (star key)to switch the display betweentip, ring and mutual. Mutual isnot used for locating opens.
Record these results forcustom cable programmingin the Auto-Cal function.
For this example, connectthe red and black leads onlyto the Cable Self Test Circuit(see above).
On
Reset
Opens
OR
OR
Operation
Section 1
Page 43
15K–1200 ohms
Limits of Opens Functions:Normal Mode and Special Mode
Dirty Opens:
Total CableDistance, ifLoaded:
Normal Special
>15K ohmsPartial Opens:
>15K ohms 15K–1200 ohms
100,000 ftor
30480 m
3000 ft/914 m(from CO)
Load Coils 1: Readsthrough
Reads to within10% of the first
6000 ft/1829 m(between loads)
10,000 ftor
3048 m
Total CableDistance,Non-loaded:
100,000 ftor
30480 m
1 Early software versions of the 900/900M Series test sets arenot equipped to count load coils. To determine if your set isequipped to do load coil counts, press the OPENS key. If theset is so equipped, the menu includes a “load coil count”option.
Note: In order to successfully locate an OPEN, partial OPEN,or dirty OPEN, the test set operator must have a goodknowledge of the cable plant (splice points, load coil locations,access points, etc.). This will help in section analysis (see page61). Voltage, Capacitance and Resistance measurements alongwith isolation techniques, are a must for cable fault location.
Operation
Section 1
Page 44
Splits
Hook-up: As instructed on the unit’s display screen– varies by application, see p. 46
About the Splits TestUse “LOCATE SPLIT” in the OPENS function to locatesplits of two or more pairs open at both ends of thesection. The pairs must have NO opens, shorts, grounds,or battery crosses. You must know the length of the cablesection. The pair capacitance must be balanced (seehookup examples for balance check following theflowchart.)
When a pair has been “corrected” by splitting the pairsback at a different location, excessive crosstalk mayresult. To correct the original split and the “correcting”split, use the “far-end to split” measurement to get thedistance between the splits. Then get between the twosplits, disconnect the wires, and measure to the splitsusing the simple splits hook-up to remeasure one split ineach direction.
Note: Splits can only occur at splice points. It is recommendedto test for a split from both ends of the section, then averagethe distances and open the splice point closest to this average.
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testingprocedure) follow standard procedures for de-energizing anddischarging cables.
Operation
Section 1
Page 45
Splits
Hook-up: As instructed on the unit’s display screen– varies by application, see p. 46
OnReset
Opens
Turn unit on.Disregard this step if the unit is on.
Normal, Special,Split Locate,Load Coil Count
Use keypad to typesection length. Use arrowkeys to move cursor toedit or correct number.
Use arrow keys to scrolldisplay to line up withSplit Locate selection.
Distance to split results,farend to split results
Check capacitivebalance or bypass
Hookup 1 instructionsfor balance check
Balance check results
Section length
Move clips as instructedfor Hookup 2
Endof
Test
See examples on the nextpage for Hookup 1 and 2.
If capacitance balance ispoor, press the ✽ (star key)to determine whichconductor causes theimbalance. Correct theproblem before continuingthe test.
Hookup as instructed for split locate
OR
OR
Operation
Section 1
Page 46
Example Splits Hookups
Capacitive Balance Check
Pair 3
Hookup 1:GREEN to PAIR 1 shorted to PAIR 3BLACK to SPLIT 2RED to GOOD 2
Pair 1
Pair 2B
R
G
Hookup 2:RED to GOOD 1 BLACK to SPLIT 1
GREEN to PAIR 2 shorted to PAIR 3 Pair 3
Pair 1
Pair 2
R
B
G
Operation
Section 1
Page 47
Split Locate Hookup
Hookup:RED to GOOD 1BLACK to SPLIT 1GREEN to SPLIT 2YELLOW to GOOD 2 shorted to PAIR 3 Pair 3
Pair 1
Pair 2
R
B
G
Y
Operation
Section 1
Page 48
AC Line Test
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
About the AC Line TestUse AC LINE TEST to automatically evaluate a workingpair. You can measure slope with a step-tone generator ora 3M brand 1020B test line or other equipment thatperforms two-way loss measurement (not available in the945/945M). Use the appropriate blue keys to verifyresults before taking corrective action.
To be sure you can dial to the farend test lines, learnabout the unit’s LOSS and NOISE functions (found inthis section of the manual) before running AC LINETEST.
Attach the leads as shown, then turn the unit on.
At the end of the test, 900-T-series units have the optionof storing the results for later retrieval in the terminalmode (for more information, see the Terminal Emulationmanual for your unit).
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testing procedure)follow standard procedures for de-energizing and dischargingcables.
Operation
Section 1
Page 49
AC Line Test
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
Note: This chart shows the tests in order as they run foreach of three testline types in a typical AC Line Test. Thetest and diagnostics may differ for your application.
GROUND
*See 3M 1020B Operators Manual for instructions.
AC LINE TEST
VOLTAGE
CURRENT
LOSS
NOISE
PWR INFLUENCE
BALANCE
DIAGNOSIS
ENDOF
TEST
3M 1020 MILLIWATT STEP TONE
LOSSLOSS
NOISE
COMMAND*
SLOPE
DIAGNOSIS
On some floating-tipswitches such as#5 ESS, groundresistance cannotbe measured as theswitch operates ona floating ground.
Available in 900-T-Series test sets only:
NO STORE RESULTS? YES
EDIT TITLE
GO TO STEPTONE OR END
ENDOF
TEST
DIAGNOSIS
YES
NO GO TODC LINETEST
Operation
Section 1
Page 50
Ringers
RED to RINGBLACK to TIPGREEN to GROUND
Hookup:R
B
G
About the Ringers TestUse the RINGERS key to count the ringer equivalencesand display bell circuit wiring configuration at thesubscriber premises, based on a type 5200 telephonehaving a 1.0 ringer equivalence, and to check for thepresence of a maintenance test unit (MTU) at thesubscriber premises.
To count ringers on a pair, connect at the subscriberprotector, remove cable plant and press the RINGERSkey. The 900/900M Series test set shows ringer wireconfiguration as bridged, wired tip, or wired ring.Exceptions to these wiring configurations are numerousand we do not attempt to list them.
Note: Resistance faults, as well as capacitive imbalance, cancause false readings such as “RESISTANCE TOO LOW” or“INVALID RINGERS HOOKUP.”
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testingprocedure) follow standard procedures for de-energizing anddischarging cables.
Operation
Section 1
Page 51
Ringers
RED to RINGBLACK to TIPGREEN to GROUND
Hookup:R
B
G
On
Reset Turn unit on.Disregard this step if the unit is on.
Endof
Test
“PLEASE WAIT” until theresults appear.
Results: ringer count andwiring configuration
Use arrow keys tomove cursor to line upwith Ringer selection.
RingerRingers, MTUTest
You can select MTU Test tocheck for the presence of amaintenance test unit atthe subscriber premises.
OR
OR
Operation
Section 1
Page 52
REG
RED to RINGBLACK to TIPGREEN to GROUND
Hookup:R
B
G
About the REG TestUse the REG key to detect loop extenders, RangeExtenders With Gain (REGs) or Dial Long Line (DLL)adapters in long subscriber loops.
The unit displays two-way loop resistance; it alsoindicates internal resistance of C.O. wiring, coils andbattery as C.O. resistance measurements.
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testingprocedure) follow standard procedures for de-energizing anddischarging cables.
Operation
Section 1
Page 53
REG
RED to RINGBLACK to TIPGREEN to GROUND
Hookup:R
B
G
On
Reset Turn unit on.Disregard this step if the unit is on.
RegListen for dialtone
Loop extender status
Endof
Test
Loop resistance andCO resistance
The C.O. Switch typeidentifies thetip-to-ground on-hookresistance; if there areunusual line cards,select ‘unknown’ C.O.type then enter thetip-to-ground on-hookresistance. You canmeasure the resistancein the C.O. directly onthe frame by using theOHMS key.
Note: On some floating-tip switches such as #5 ESS, groundresistance cannot be measured as the switch operates on afloating ground.
OR
OR
Operation
Section 1
Page 54
Loss
RED to RINGBLACK to TIPGREEN to GROUND
Hookup:R
B
G
About the Loss TestUse the LOSS key to measure attenuation in subscriberloops. The unit calls up a milliwatt or step-tone generatorand measures and displays test tone frequency and loss.
Note: If the milliwatt number dials to a combination line (10seconds of milliwatt tone followed by quiet line), you can pressthe NOISE key after the loss measurement to perform a noisetest and power influence calculation on this line.
The 900/900M Series test set can also measure loss froma tone source on a vacant pair.
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testingprocedure) follow standard procedures for de-energizing anddischarging cables.
Operation
Section 1
Page 55
Loss
RED to RINGBLACK to TIPGREEN to GROUND
Hookup:R
B
G
Dial
Dial
On
Reset
Disregard this step if theunit is on.
Loss
End ofTest
You can hear the unitdialing the number,testline going off-hook,and the test tones.
Note: If the milliwatt number dials to a combination line (10seconds of milliwatt tone followed by quiet line), you canpress the NOISE key after the loss measurement to perform anoise test and power influence calculation on this line.
The unit measuresvoltage on the line. If thedisplay shows “VOLTAGELOW,” as on a vacantpair, you can press the ✽(star key) to measure lossfrom a tone sourceconnected at the far end.
Turn unit on.
Dial types selection
Use arrow keys to movecursor;Use keypad to type innew number, if needed
Move ✽ to select type
Telephone number toselect or edit
Listen for dial tone
Unit dials numberand displaystests results
Select to dialor measure.
You can press the #(pound key) to bypass thedial routine.
Select groundstart or continue
OR
OR
OR
OR
Operation
Section 1
Page 56
Noise
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
About the Noise TestUse the NOISE key to dial to a quiet line and measureunwanted signal in subscriber loops. The unit displaysnoise metallic, power influence (noise to ground), andcalculated balance. Some units are equipped to measurelongitudinal balance* with the Noise routine.
The 900/900M Series test sets can also measure noise,power influence and calculate balance on a vacant pair.The far end should be terminated with a 600-ohm balancetermination for this process.
Note: If your test set is equipped with an optional backlight,you must turn it off for the noise test. The activated backlightaffects the line noise test results.
CautionIf hazardous voltage warnings are displayed when the test set isswitched on or reset (or at any time during the testingprocedure) follow standard procedures for de-energizing anddischarging cables.
*Longitudinal balance test in accordance with ANSI/IEEEstandard 455–1985.
Operation
Section 1
Page 57
Noise
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup: R
B
G
The unit measures voltageon the line. If the displayshows “VOLTAGE LOW,”as on a vacant pair, youcan press the ✽ (star key)to measure noise with abalance terminationconnected at the far end.
Dial
On
ResetDisregard this step if theunit is on.Turn unit on.
Dial types selection
Use arrow keys to movecursor;Use keypad to type innew number, if needed
Move ✽ to select type
Telephone number toselect or edit
Listen for dial tone
Select to dial ormeasure.
You can press the #(pound key) to bypass thedial routine.
Select groundstart or continue
DialMetallic noisemeasurement,results
Unit measures anddisplays power influence
End ofTest
Unit calculates anddisplays line balance
For access code, dial thenumber manually.
Select tomeasure noiseor longitudinalbalance.
NoiseYou can press the #(pound key) to measurelongitudinal balance.
Press DIAL key when youhear dial tone.
Unit dials number, beginsmeasurement when quietline connects.
OR
OR
OR
OR
Operation
Section 1
Page 58
Noise Routine – Measure LongitudinalBalance 1
RED to RINGBLACK to TIPGREEN to GROUNDED SHIELD
Hookup:R
B
G
1 Longitudinal balance test in accordance withANSI/IEEE standard 455–1985.
The unit measureslongitudinal balanceand displays the results.The results arecontinuously updatedon the screen.
On
Reset
Disregard this step if theunit is on.Turn unit on.
Select to dial ormeasure.
You can press the *(star key) to use thedial function.
Unit measures, displayslongitudinal balance.
Endof
Test
Select to measurenoise or longitudinalbalance.
Noise
You can press the #(pound key) to measurelongitudinal balance.
OR
OR
SECTION 2
Page 59
Special Applications
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1.1 For resistance faults at more than one location on apair, the resistance fault locate operation gives a
distance to the average of the fault locations. Forexample, if a 3000 ft/914 m cable has one 10k ohm faultat 1000 ft/304 m and a 100k ohm fault at 2000 ft/610 m,the unit should show a 9.09k ohms fault at about 1091ft/333 m (the average), or just past the major fault.
Unit averages the distances to the faultsand shows the distance-to-fault to be here.
10k ohms 100k ohms
Special Applications
Section 2
Page 60
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2.1 Where water in the cable causes a resistance fault, theunit measures to the middle of the wet section, or the
average of the total resistance faults. Use the followingprocedure to estimate the length of cable damaged by water:
a. Measure the length of the cable (DTS) with theRFL function.
b. Measure the tip or ring length of the cable again,using the OPENS function.
c. The equivalent length of water in the cable is theOPENS measured length minus DTS measured
length divided by two.
Example:DTS reading = 680 ft/207 m
OPENS reading = 1130 ft/344 mlength of wet cable = (1130-680) = 225 ft/68.5 m
2
DTS = 680ft/207 mOPENS = 1130ft/344 m
1130 - 680 = 450450 ÷ 2 = 225 ft/68.5 m of wet cable
Water in Cable - Resistance Faulted Pair
Special Applications
Section 2
Page 61
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3.1 To analyze a section of cable, first use theRESISTANCE FAULT LOCATE function to
measure as many resistance faults as you can in thesection. Next, use the OPENS key to measure to as manyopen faults in the section as possible, then refer to thechart below:
Pattern of Symptoms Look for:
Several light faults withmostly ring-battery crosseswith tips clear.
Water in the cable at somelocation other than a spliceor encapsulation.
Several high resistancetroubles with shorts, cross-es and grounds on both tipand ring with some tipsopen.
Water in a splice case orencapsulation.
Both solid and light troubleswith some conductorsshorted and some open;many faults.
Physical damage to thecable due to stakes,trenches, construction, etc.
Special Applications
Section 2
Page 62
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4.1 The electrical length of load coils makes a pair withload coils measure longer than the actual cable
length. For example, load coil leads are usually 24 gauge(AWG). If the conductor under test is 19 gauge, afive-foot or 1.5 meter stub adds more than 32 feet or 9meters to your measurement, plus the electrical length ofthe coil itself. The total error from each load coil on thepair varies from 91 feet (27 meters) to more than 480feet, depending on the conductor gauge and the coil. Thetable below lists the amount to subtract from yourmeasurement for each load coil, based on a five-foot stubat the default temperature (70° F or 21.1° C).
Electrical Length (Feet/meters) of Coil and Stub*
Code 19 AWG 22 AWG 24 AWG 26 AWG Ohms
632 470/143 235/72 147/45 91/28 4.14
652 484/147 242/74 150/46 94/29 4.17
662 480/146 240/73 149/45 95/29 4.25
* Calculated for two five-foot 24 AWG stubs at 70° F.
Special Applications
Section 2
Page 63
Counting Load Coils 1
RED to RINGBLACK to TIP
Hookup:R
B
On
Reset
Opens
Turn unit on.
Normal, Special,Split Locate, LoadCoil Count
Move ✽ to select testtype– Load Coil Count
Results of load coilcount
Disregard this stepif the unit is on.
Endof
Test
The load coil count takes 1.5minutes to complete. Whenthe unit displays the results,you can press the ✽ (star)key to repeat the test.
OR
OR
1 Early software versions of the 900 Series/900M Series test setsare not equipped to count load coils. To determine if your set isequipped to do load coil counts, press the OPENS key. If theset is so equipped, the menu includes a “load coil count”option.
Special Applications
Section 2
Page 64
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Step 1 – Setup:• Disconnect the open conductor at both ends• Determine the length of the section under test and
record as measurement “D.”
Step 2 – Hookup:• Red – open conductor• Black and green – shield or other conductor
Step 3 – Measure from near end:• Press the ON/RESET key, then the OPENS key
and select NORMAL MODE• Press the # (pound) key and select AIRCORE
CABLE• Record the RING measurement as “A.”
Step 4 – Measure from far end:• Repeat Step 3 from the far end.• Record the RING measurement as “B.”
Step 5 – Calculate:
If C = A + B and D = section length, use this formulato calculate distance to open from end A or B:
d�(A or B)� D
C
Example:If A = 240ft, B = 110ft, and D = 290ft,then C = A + B = 240 + 110 = 350ftdistance to open from end B:
d� B� DC
�110� 290
350� 91.14 ft
Special Applications
Section 2
Page 65
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Step 1 – Setup:• Disconnect shield bond to isolate the shield at
both ends.• Determine the length of the section under test and
record as measurement “D.”
Step 2 – Hookup:• Red – shield• Black and green – ground rod; or when induction
is interfering, connect to several bunched vacantpairs.
Step 3 – Measure from near end:• Press the ON/RESET key, then the OPENS key
and select SPECIAL MODE.• Press the # (pound) key and select AIRCORE
CABLE.• Record the RING measurement as “A.”
Step 4 – Measure from far end:• Repeat Step 3 from the far end.• Record the RING measurement as “B.”
Step 5 – Calculate:If C = A + B and D = section length, use this formulato calculate distance to open from end A or B:
d�(A or B)� D
C
Example:If A = 73.2 m, B = 33.5 m, amd D = 88.4 m,then C = A + B = 73.2 + 33.5 = 106.7 mdistance to open from end A:
d� A� DC
�73.2� 88.4
106.7� 60.6 m
Special Applications
Section 2
Page 66
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7.1 With a resistance measurement, you can get theequivalent length in feet for a different temperature,
using the following procedure.
1. Press to turn unit on.
2. Press .
3. Select SET TEMPERATURE using keys. Press .
4. Enter temperature to convert. Press .
5. Select DISTANCE TO OHMS using keys; press .
6. Enter length to convert. Press .
7. Select gauge to convert using keys. Press .
8. Press .
9. Press .
10. Select SET TEMPERATURE using keys. Press .
11. Enter conversion temperature. Press .
12. Select OHMS TO DISTANCE using keys. Press .
13. Display shows converted temperature and footage.
Example:500 feet of 24 gauge at 50� to convert to 95�.
Complete steps 1, 2, and 3.
For step 4, enter temperature as 50, and press .
Complete step 5.
For step 6, enter 500 feet, and press .
Complete steps 7 to 10.
For step 11, enter temperature as 95 and press .
Complete step 12.
Step 13 shows converted length 454 feet at 95�.
SECTION 3
Page 67
Specifications
�� �������� ������������ ������ � ����
A. Measurements
Function Range Resolution AccuracyAC Voltage: 0 to 75 VAC 0.1V 0.7V
75 to 250 VAC 1.0V 3%
DC Voltage: 0 to 100 VDC 0.1V 0.5V100 to 350 VDC 1.0V 3%
DC Current: 0 to 100 mA DC 0.1 mA 0.3 mA(Zin = 430 ohms)
Resistance1: 0 to 100 Mohms 100 ohms 1% @ 50 kohms @ 50 kohms
Opens1:(normal mode)0 to 9.99 kft 10 ft @ 10 kft +1%10 k ft to 100 kft 100 ft +1/–10%0 to 30000 m 3 m @ 500 m 1.5 m ±1%
@ 500 m
Tolerance to Leakage, Normal Mode: >15 kohm to ground / 190 kohm to battery
Opens1:(special mode)0 to 999 ft 1 ft +1%1 kft to 10 kft 100 ft @ 10 kft +1/–10%0 to 30000 m 3 m @ 500 m 6m ±1%
@ 500 mTolerance to Leakage, Special Mode: >1200 ohms to ground / 18 kohms to batteryNote: 1 Perform a self-calibration before taking the readings.
B. Resistance Fault LocateNote: Accuracy is dependent on power influence noise; the resistancefault specifications are for low noise situations.
Function Range Resolution Accuracy 1,2
Fault Range: Up to 30 MohmsResistance to Fault:2 0 to 9 ohms 0.01 Ohm +0.1% RTS (@ 70° F no noise) +0.01 Ohm
10 to 99 ohms 0.01 Ohm +0.1% RTS +0.01 Ohm
100 to 999 ohms 0.1 Ohm +0.2% RTS1k to 7 kohms 1.0 Ohm +1.0% RTS
Resistance to Distance Conversion Resolution:3 1 ft to 1,000 ft 0.1 ft
1k ft to 10k ft 1.0 ft
Specifications
Section 3
Page 68
10k ft to 100k ft 10.0 ft1 to 99 m 0.1 m 100 to 999 m 1.0 m1000 to 30000 m10.0 m
Temperature Sensor: 0° to 140° F 1° F +2° F–18° to 60° C .5° C +1° C
Noise Immunity: 7 VAC limit for all frequencies
Note: 1 See figures below for accuracies. All resistance to fault measurement accuracies have an added factor of(2 x 10 -8) RF ohms.
2 Single pair hook-up measurement accuracy is strictly dependent on whether the reference pair is exactly the same electrical length as the faulted pair. Accuracies aredoubled for single pair hook-up.
3 Accuracy depends on correct temperature setting as well as gauge accuracy of copper. The temperature can beread by the built-in sensor or can be operator-entered.2 –
----
1.5–----
1 –----
.5 –----
0 –
Accuracy in ohms for Various Fault Resistances
MaximumError inohms
Resistance to Strap in ohms2 10 20 404
20 Mohms
10 Mohms
<1 Mohm
30 Mohms
100 400 10002001
0
5
10
15
20
25
30
35
40
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
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30 Mohms
20 Mohms
10 Mohms
< 1 Mohm
Specifications
Section 3
Page 69
C. OutputsTones Frequency Level ImpedanceIdentification: 577.5 Hz 6V PK to PK 100 ohms
(Current limitedto 6 mA)
Precision Tones: 1004 +1 Hz 0 dBm + 0.2 dB 600 OhmHarmonic distortion: <45 dB (up to 10th harmonic)
D. EnvironmentOperation Storage
Temperature: 0° to +140° F –40° to 165° F–18° to 60° C –40° to 74° C
Humidity: 0 to 100% 0 to 100% (condensing) (condensing)
Altitude: 0 to 15,000 ft 0 to 40,000 ft0 to 5000 m 0 to 12000 m
Shock: Can withstand a drop onto a wood surfacefrom a distance of four ft (1.25 m)
E. Dimensions
Height 7.0 in/ 18 cmWidth 10.5 in/ 27 cmDepth 7.5 in/ 19 cmWeight 7.5 lbs/ 3.4 kgCord length 5 ft/ 1.5 m
F. Battery Power
The operating time between battery change-out or charges dependson temperature of set and operation modes used.
For non-rechargeable batteries typical operating time is about 200hours between battery change-out.
For rechargeable batteries typical operating time is about 80 hoursbetween charges.
Specifications
Section 3
Page 70
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A. Measurements
Function Range Resolution AccuracyAC Voltage: 0 to 75 VAC 0.1V 0.7V
75 to 250 VAC 1.0V 3%DC Voltage: 0 to 100 VDC 0.1V 0.5V
100 to 350 VDC 1.0V 3%DC Current: 0 to 110 mA DC 0.1 mA 0.3 mA
(Zin = 430 ohms)
Resistance1: 0 to 100 Mohms 100 ohms 1% @ 50 kohms @ 50 kohms
Loss: –40 to +10 dBm 0.1 dB 0.2 dB(Zin = 600 ohms) 200 to 5,000 Hz
Noise Metallic2: 10 to 50 dBrnC 0.1 dB 0.5 dB0 to 10 dBrnC 0.3 dB 2.0 dB(Zin = 600 ohms)
Noise to Ground: 40 to 100 dBrnC 0.1 dB 0.5 dB
(Zin = 600 ohms)
Opens1:(normal mode)0 to 9.99 kft 10 ft @ 10 kft +1%10k ft to 100 kft 100 ft +1/–10%0 to 30000 m 3 m @ 500 m 1.5 m ±1%
@ 500 m
Tolerance to Leakage, Normal Mode: >15 kohm to ground / 190 kohm to battery
Opens1:(special mode)0 to 999 ft 1 ft +1%1 kft to 10 kft 100 ft @ 10 kft +1/–10%0 to 30000 m 3 m @ 500 m 6m ±1%
@ 500 m
Tolerance to Leakage, Special Mode: >1200 ohms to ground/18 kohms to batteryFrequencyMeasurement: 20 to 20,000 Hz 1 Hz 2 Hz
during Loss, single frequency onlyGroundResistance: 0 to 500 ohms 1 Ohm 3 ohmsLoop and C.O.Resistance: 0 to 5000 ohms 1 Ohm +10% +
50 ohms(read through the REG key assuming on-hook resistance is known)Note : 1 Perform a self-calibration before taking the readings.
2 C-message specifications have an additional frequency-dependent tolerance. Refer to “IEEE Standard 743–1984.” The 945/945M far exceeds these tolerances. For most frequencies the total error is less than 0.7 dB.
Specifications
Section 3
Page 71
B. Outputs
Tones Frequency Level ImpedanceIdentification: 577.5 Hz 6V PK to PK 100 ohms
(Current limited to 6 mA)
Precision Tones: 1004 +1 Hz 0 dBm + 0.2 dB 600 OhmHarmonic distortion: <45 dB (up to 10th harmonic)
Dial Frequency RemarksDTMF: Standard 100 msec on
100 msec offmeets CCITT Q.23 Standard for frequency and amplitude i.e. +1 Hz @ –10 dBm +1 dB
Dial Pulse: 10 pulses 60 msec break per sec 40 msec make
600 msec between digits
C. EnvironmentOperation Storage
Temperature: 0° to +140° F –40° to 165° F–18° to 60° C –40° to 74° C
Humidity: 0 to 100% 0 to 100% (condensing) (condensing)
Altitude: 0 to 15,000 ft 0 to 40,000 ft0 to 5000 m 0 to 12000 m
Shock: Can withstand a drop onto a wood surfacefrom a distance of four feet (1.25 m)
D. Dimensions
Height 7.0 in/ 18 cmWidth 10.5 in/ 27 cmDepth 7.5 in/ 19 cmWeight 7.5 lbs/ 3.4 kgCord length 5 ft/ 1.5 m
E. Battery Power
The operating time between battery change-out or chargesdepends on temperature of set and operation modes used.
For non-rechargeable batteries typical operating time is about 200hours between battery change-out.
For rechargeable batteries typical operating time is about 80 hoursbetween charges.
Specifications
Section 3
Page 72
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A. MeasurementsFunction Range Resolution Accuracy
AC Voltage: 0 to 75 VAC 0.1V 0.7V75 to 250 VAC 1.0V 3%
DC Voltage: 0 to 100 VDC 0.1V 0.5V100 to 350 VDC 1.0V 3%
DC Current: 0 to 100 mA DC 0.1 mA 0.3 mA(Zin = 430 ohms)
Resistance1: 0 to 100 Mohms 100 ohms 1% @ 50 kohms @ 50 kohms
Loss: –40 to +10 dBm 0.1 dB 0.2 dB(Zin = 600 ohms) 200 to 5,000 Hz
Noise Metallic2: 10 to 50 dBrnC 0.1 dB 0.5 dB
0 to 10 dBrnC 0.3 dB 2.0 dB(Zin = 600 ohms)
Noise to Ground: 40 to 100 dBrnC 0.1 dB 0.5 dB
(Zin = 600 ohms)
LongitudinalBalance withTone Option3: 62 to 51 dB 0.1 dB 2.0 dB
51 to 40 dB 0.1 dB 1.0 dB
Opens1:(normal mode)0 to 9.99 kft 10 ft @ 10 kft +1%10k ft to 100k ft 100 ft +1/–10%0 to 30000 m 3 m @ 500 m 1.5 m ±1%
@ 500 m
Tolerance to Leakage, Normal Mode: >15 kohm to ground / 190kohm to battery
Opens1:(special mode)0 to 999 ft 1 ft +1%1 kft to 10 kft 100 ft @ 10 kft +1/–10%0 to 30000 m 3 m @ 500 m 6m ±1%
@ 500 m
Tolerance to Leakage, Special Mode: >1200 ohms to ground / 18 kohms to battery
FrequencyMeasurement: 20 to 20,000 Hz 1 Hz 2 Hz(during Loss, single frequency only)
Specifications
Section 3
Page 73
Measurements continued...Function Range Resolution Accuracy
GroundResistance: 0 to 500 ohms 1 Ohm 3 ohms
Loop and C.O.Resistance: 0 to 5000 ohms 1 Ohm +10% +
50 ohms(read through the REG key assuming on-hook resistance is known)
Caller I.D.Option: –4 dBm to –32 dBm
Note: 1 Perform a self-calibration before taking the readings.2 C-message specifications have an additional frequency-
dependent tolerance. Refer to “IEEE Standard 743-1984.”The 965/965M far exceeds these tolerances. For mostfrequencies the total error is less than 0.7 dB.
3 The optional longitudinal balance function obtains a resultin agreement with “IEEE STANDARD 455-1985 StandardTest Prodedure for Measuring Longitudinal Balance forTelephone Equipment Operating in the Voice Band” at thespecified tolerance for power influence less thanapproximately 80 dBrnc. When power influence is above80 dBrnc, the test set reverts to a hybrid of the IEEEmethod and the method of calculating longitudinal balanceby taking the difference between power influence andnoise metallic.
4 The splits function does not have accuracy tolerances.
B. Resistance Fault Locate
Note: Accuracy is dependent on power influence noise; the resistancefault specifications are for low noise situations.Function Range Resolution Accuracy 1,2
Fault Range: Up to 30 MohmsResistance to Fault:3 0 to 9 ohms 0.01 Ohm +0.1% RTS
+0.01 Ohm(@ 70° no noise) 10 to 99 ohms 0.01 Ohm +0.1% RTS
+0.01 Ohm100 to 999 ohms 0.1 Ohm +0.2% RTS1k to 7 kohms 1.0 Ohm +1.0% RTS
Resistance to Distance Conversion Resolution:3 1 ft to 1,000 ft 0.1 ft
1k ft to 10k ft 1.0 ft10k ft to 100k ft 10.0 ft1 to 99 m 0.1 m 100 to 999 m 1.0 m1000 to 30000 m10.0 m
Temperature Sensor: 0° to 140° F 1° F +2° F–18° to 60° C .5° C +1° C
Noise Immunity: 7VAC limit for all frequencies
Specifications
Section 3
Page 74
Note: 1 See figures next page for accuracies. All resistance to fault measurement accuracies have an added factor of (2 x 10 -8) RF ohms.
2 Single pair hookup measurement accuracy is strictly dependent on whether the reference pair is exactly the same electrical length as the faulted pair. Accuracies aredoubled for single pair hookup.
3 Accuracy depends on correct temperature setting as well as gauge accuracy of copper. The temperature can be read by the built-in sensor or can be operator-entered.
2 –----
1.5–----
1 –----
.5 –----
0 –
Accuracy in ohms for Various Fault Resistances
MaximumError inohms
Resistance to Strap in ohms2 10 20 404
20 Mohms
10 Mohms
<1 Mohm
30 Mohms
100 400 10002001
0
5
10
15
20
25
30
35
40
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
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�������� ��� ���� � �� ����
30 Mohms
20 Mohms
10 Mohms
< 1 Mohm
Specifications
Section 3
Page 75/(76 blank)
C. Outputs
Tones Frequency Level ImpedanceIdentification: 577.5 Hz 6V PK to PK 100 ohms
(Current limited to 6 mA)
Precision Tones: 404, 1004, 0 dBm + 0.2 dB 600 Ohm2804 +1 Hz
Harmonic distortion: <45 dB (up to 10th harmonic)User-Entered Tone:Frequency Resolution Frequency AmplitudeRange Accuracy Accuracy2 to 100 Hz +0.1% +1% +1dB100 to 1 kHz +1.0% +1% +1dB1 kHz to 10 kHz +3.0% +1% +1dB10 kHz to 20 kHz +3.0% +1% +3dBHarmonic distortion: <45 dB (up to 10th harmonic)Dial Frequency RemarksDTMF: Standard 100 msec on
100 msec offmeets CCITT Q.23 Standard for frequency and amplitude i.e. +1 Hz @ –10 dBm +1 dBDial Pulse: 10 pulses 60 msec break
per sec 40 msec make R–T600 msec between digits
D. EnvironmentOperation Storage
Temperature: 0° to +140° F –40° to 165° F–18° to 60° C –40° to 74° C
Humidity: 0 to 100% 0 to 100% (condensing) (condensing)
Altitude: 0 to 15,000 ft 0 to 40,000 ft0 to 5000 m 0 to 12000 m
Shock: Can withstand a drop onto a wood surfacefrom a distance of four ft (1.25 m)
E. DimensionsHeight 7.0 in/ 18 cmWidth 10.5 in/ 27 cmDepth 7.5 in/ 19 cmWeight 7.5 lbs/ 3.4 kgCord length 5 ft/ 1.5 m
F. Battery PowerThe operating time between battery change-out or charges dependson temperature of set and operation modes used.For non-rechargeable batteries typical operating time is about 200hours between battery change-out.For rechargeable batteries typical operating time is about 80 hoursbetween charges.
SECTION 4
Page 77Page 77
Care & Maintenance
1. TEST LEAD AND BATTERY INSTALLATION INSTRUCTIONS
Step 1 Insert the testlead plug into the top fourholes.
900 /900M Series TestSet
900-T-Series Test Set
Care & Maintenance
Section 4
Page 78
Step 2 Press downfirmly. Test leads are nowinstalled.
Step 3 Invert caseand remove the batterycover by loosening the sixscrews with a flat-bladescrewdriver.
Step 4 Installbatteries, matching thepolarity markings (+ and –)on the batteries with thosein the bottom of the batterybox.
Note: Some models are equipped with battery “sticks” toprevent data interruption in the units. Do not separate thebatteries.
900-T-Series Test Set
900 /900M Series TestSet
Care & Maintenance
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Step 5 Replace thebattery cover. Turn the uniton. The message “PLEASEIDENTIFY BATTERIESUSED” appears. Press the
(pound key) or (starkey) to identify battery type,then press the AUTO CALkey and run self calibration.
Note: When installing new rechargeable batteries, orto compensate for weak rechargeable batteries, usethe internal battery charger to overcharge the cells(18 hours, maximum). Follow the instructions on thedisplay to connect the leads to an external 12-volt source,such as a Dynatel Model 1658 or 1678 battery charger kit.Turn the unit on. Press the AUTO-CAL key. Use thearrow keys to select the “CHARGE BATTERY”function, and press the (star key). Press the (pound key) to select the overcharge function, andpress the (star key) to activate the chargingprocess. The unit turns off automatically whencharging is complete.
2. BATTERY MAINTENANCE2.1 Rechargeable batteries last longer when properly
recharged. The unit keeps track of power usage,displays an estimate of the battery charge, and displays amessage prompting you to charge the batteries at thecorrect time.
Care & Maintenance
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Battery Types and Capacity Table
ALKALINENICKEL-CADMIUM*
* Zinc-carbon cells are not recommended, as they havelower capacity and they may leak.
** Typical use is considered four hours per day of power ONin the Voltage mode.
5“C” CELLS
14A
26-0000-4787-3
>6 VOLTS
5.9 – 5.75 VOLTS
<5.75 VOLTS
NO
6 WEEKS
QUANTITYSIZE
NEDA NUMBER
ORDER NUMBER
“BATT OK”
“BATT LOW”
SOFTWARE SHUTDOWN
RECHARGEABLE
EXPECTED BATT LIFE(TYPICAL USE):**NEW/100% CHARGE
“CHARGE BATTERIESTONIGHT, PLEASE:”
5“C” CELLS
26-1006-2163-5
>6 VOLTS
5.9 – 5.75 VOLTS
<5.75 VOLTS
YES
2 WEEKS
1 DAY
2.2 When the unit displays “BATTERIES NEEDCHARGE *,” you cannot use the unit without
recharging or replacing the batteries. Press the (starkey) as prompted to put the unit in charge mode.
CautionPromptly remove discharged alkaline batteries from the unit; theycan leak and damage the contacts. Damage of this kind voidsyour warranty.
2.3 Damaged nickel-cadmium batteries can make thebattery status message go quickly from
“CHARGE TONIGHT” to “NEED CHARGE.” If thishappens, discharge the batteries as much as possible, thenovercharge them with either the internal or an externalcharger. Repeat this cycle twice.
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A. When To Charge Or Replace Batteries2.4 The unit displays an estimate of battery charge:
voltage for alkaline batteries and percent of powerused for rechargeable batteries. The unit also displays“CHARGE BATTERIES ” to prompt you to recharge thebatteries (if rechargeable), or replace them with eitheralkaline dry cells or a spare set of rechargeable batteries.
2.5 With the batteries removed, the unit can retainstored telephone numbers up to three minutes.
After ten minutes without battery power, stored numbersare lost. When you install a freshly-charged set ofnickel-cadmium batteries, press the AUTO CAL key andselect the battery identification option. Answer thequestions correctly to make the display indicate full charge.
B. Internal Battery Charging2.6 To use the internal battery charger, follow the
instructions on the display to attach the leads to a12-volt source (e.g., a Dynatel 1678 Battery Charger Kitfor one unit, or 1658 for up to three units). Turn the uniton and press the AUTO CAL key. Press the (star key)to select CHARGE BATTERY, then press the (starkey) for normal charging or the (pound key) forovercharging. The unit turns off automatically whencharging is complete.
C. External Battery Charging2.7 If the battery charge gets too low to turn the unit
on, take off the battery cover and remove thebatteries. Recharge the cells with an external(user-supplied) AC-powered battery charger. Charge thecells at approximately 180 mA for no more than 18 hours.
Important:
Prolonged overcharging (maximum 18 hours) reducesbattery life.
Care & Maintenance
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R B G Y
3. CHECK OPENS PERFORMANCE3.1 To check OPENS performance, use the Cable Self
Test Circuit included with your set, shown above.Attach the red lead to terminal “R” and the black lead toterminal “B.” Press the OPENS key. The results in feet ormeters should be in the ranges shown in the table below.
Note: The test set circuits are more accurate than the Cable SelfTest Circuit, so the limits in the table below are wider than in theSpecification section.
Opens Self Test Limits in feet/meters
Capaci-tance
Air Core
Jelly-Filled
2-Pair 5-PairDrop Drop
MAX
MIN
MIN
MIN
MIN
MAX
MAX
MAX
NormalTip
or Ring
NormalMutual
SpecialTip
or Ring
SpecialMutual
Cable Type:
9.35 nF
.01065 uF
9.35 nF
8.75 nF
.01125 uF
395/120
450/137
595/181
680/207
370/113
475/145
560/171
715/218
425/130
330/101
595/181
400/122
350/107 320/98 330/101
375/114365/111
595/181 595/181
300/91 310/94
385/117 395/120
8.75 nF
.01125 uF
680/207 680/207 680/207
560/171
715/218
560/171
715/218
560/171
715/218
.01065 uF
Care & Maintenance
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R B G Y
4. CHECK RESISTANCE FAULT LOCATE PERFORMANCE
4.1 The Cable Self Test Circuit (above) allows you totest the resistance fault locate function at any time.
This test is particularly important when potentiallydamaging physical conditions such as shock or prolongedsubmersion could affect performance.
Note: The test set circuits are more accurate than the Cable SelfTest Circuit; therefore, the limits in the tables following theexample flowchart are wider than in the Specification section.
4.2 Connect the test leads to the circuit terminals: redto R, black to B, yellow to Y, and green to G.
Press the RES FAULT LOCATE key. Use the separategood pair hookup and procedure in the following example.Compare the information in the tables that follow to theresults displayed by the unit. If the results fall within theranges listed, your unit works correctly.
Care & Maintenance
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Check RFL Performance FlowchartHookup (to CableSelf Test Circuit): R
B
G
Y
ResFault
Locate
On
ResetTurn unit on.
Stored setups ––Change setups
Measure DTS, orDTS known
Temperature entryoption
Select cable gauge
Select hookups
Use separate goodpair hookup
continued on next page...
Setups summaryThe display summarizesthe setups you just entered.Press ✽ to use them.
The display may tell youto “wait” while the unitruns tests.
When you complete thehookup, press ✽ to beginthe measurements.
Test set, strapshookup instruction
Fault resistance,strap checks
Display distance inunits of feet or meters
Press the ✽ (star key) to use thetemperature default (21.1°C or70°F)
Press the ✽ (star key) to choose Measure DTS
Use arrow keys toline up ✽ with 19AWG or .912mm
OR
OR
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CHECK RFL FUNCTION, continued
You can press # to repeat thetest with the most commonlyused cable gauges.
Endof
Test
“PLEASE WAIT” whileunit continues RFLmeasurement
Accuracy results
DTF=1210 ft/369 mSTF=10890 ft/3312 mDTS=12100 ft/3680 m
DTS results:DTS=12100 ft/3680 m
Min Max
Fault Resistance: 995k 1MStrap Checks:RED to GREEN 193 207RED to YELLOW 94 104
Self Test: Fault Magnitude Straps Check Table
AWG Min Max Min Max Min Max
19 11910 12290 1170 1230 10730 1107022 5986 6171 592 613 5393 555924 3755 3871 371 385 3383 348825 2970 3063 293 305 2676 275926 2347 2420 232 240 2114 218028 1479 1526 146 152 1332 1375Ohms 99.3 102.5 9.8 10.2 89.5 92.3
English RFL Self Test
70°F
****
DTS DTF STF
* Disregard the ‘move closer to fault...’ message for the self-test.
Care & Maintenance
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Metric RFL Self Test
21.1°C DTS DTF STF
wiresize min max min max min max
.912 3630 m 3746 m 356 m 375 m 3274 m 3371 m
APPENDIX
Appendix 1
Appendix
Generally Accepted Criteria for Plain OldTelephone Service
Parameter Acceptable Marginal Unacceptable
Loop Current mA ≥232 ≥20< 232 <201, 2
Circuit loss dBm ≤8.5 – >8.5Metallic Noise dBrnC ≤20 >20< 30 ≥30Power Influence dBrnC ≤80 >80<90 ≥90Balance dB ≥60 >50<63 ≤50*Station Ground Ohms ≤25 ––– > 25Slope dB ≤7.5 ––– > 7.5
Parameter Insulation Light Fault HeavyGood (Service Fault
Affected)3 (Out ofService)
InsulationResistance ≥ 3.3 MOhms >2.8 kOhms ≤2800 Ohms
< 3.3 MOhms
1 These are negative values.2 >18 to <20 mA acceptable for emergency service only.3 Lines having good insulation but equipped with ringer
isolators or selective ringing devices will test as having lightfaults on tip and ring.
NOTE: > means “more than”≥ means “more than or equal to”< means “less than”≤ means “less than or equal to”
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Appendix
Appendix 2
Notes on AC line Analysis Procedures
Loop current and circuit loss work together. When loopcurrent approaches –23 mA the circuit loss should beapproximately –8.0 dBm. If the loop current is low and thecircuit loss is less than –8.0 dBm, the problem is probably adefective loop aid. If the loop current is good and the circuitloss is high, the problem is either bridged tap or incorrectloading. If both loop current and circuit loss are bad, theproblem is incorrect resistance zoning. When circuit lossexceeds –8.5 dBm, the actual measured loss should becompared with an estimated measured loss based on loopmake–up. If they differ significantly, dial up a step tonegenerator and make a frequency run to check loading. If bothactual and estimated loss exceed –8.5 dBm and areapproximately the same, install a VF repeater to decrease theloss.
Noise and Power influence work together. If noise is highand power influence is low, the problem most likely is adefective pair. If power influence is high, the problem is anopen shield or missing ground.
For touch dialing problems, dial up a step tone generatorand make a frequency run to check for loaded bridge tap.
If in doubt, measure additional pairs. If other pairs aregood, your problem is a single bad pair. If other pairs readdefective as the one you’re working on, the problem is in thecable or complement.
For 2–party lines, a missing ringer isolator at one partycauses noise to the other party. Ringer isolators must beplaced at both parties.
Unacceptable Balance When noise and power influence areshown as acceptable, but the balance reading is not, such as:
Noise = 19.3 dBrnC (OK)Power Influence = 68.2 dBrnC (OK)Balance = 48.9 dBrnC (unacceptable)
The unacceptable balance reading is a clue that there may benoise problems during peak power periods when power
Appendix
Appendix 3/(4 blank)
influence will be higher than at the time the service call ismade. If noise was the subscriber’s complaint, then balanceis the cause of problem; if the complaint was not related tonoise, the low balance may not be a problem. Noise caused bybalance is a common cause of multiple service calls. Thenoise and power influence levels are more likely to beacceptable at the time of the service call than when thesubscriber is at home and using the phone during morning andevening peak power periods. An unacceptable balancereading is the only clue in this situation.
Telecom Systems Division
6801 River Place Blvd.Austin, Texas 78726–9000
This literature was printed in the U 3M 1